Pneumatic swab plunger



July 25, 1933- H. w. FLETCHER PNEUMATIC SWAB PLUNGER Filed Oct. 27, 1931 FIG. 3

HAROLD W. FLETCHER INVENTOR ATTORNEY Patented July 25,1933

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":rnrirriyrn'rro SWAIBTLUNGERFPY Application filed. October 27. 1931. Serial 116371.353.

pneuf liquid above the plunger seat to cushion its fall with the resultthat the plunger hits a dry seatwwith great force tending to injure the apparatus. j .It is an object of my invention to slow down the falling of the swab-plunger after its upward stroke, and to thereby prolong the cycle in its operation to -such, an extent that before the plunger reaches bottom the liquid will'have time to flow into the well and rise in the eduction tube to a pointwell above the stop seat for the plunger.

1 wish to chokedown the passage through the plunger so that the fluidbelow the plunger can pass only at a slow rate through the plunger as it falls and thus impede its fall ing velocity and also give time for the liquid to accumulate above the lower stop member.

In the drawing herewith, Fig. 1 is a central verti al section through the upper'end of the well equipmenti'orawell swabbing device.

Fig. 2 is a longitudinal section through my improved plunger. r

Fig. 3 is a section showing the plunger at the lower end of the eduction tube, spaced slightly from the stop member. p

I have illustrated myplunger in a well equipment now in use. It includes an outer casing 1, with a casing head 2 thereon. Said casing head has a lateral pipe connection 3 thereon, whereby pressure fluid may be supplied where necessary, and its upper end has a bonnet 4 screwed thereon. Said bonnet has a threaded seat 5 at its upper end to connect with the eduction tube extension 6 a and form a fluid tight joint therewith.

Within the casing head is an annular shoulder 7 to support the head 8 upon the eduction tube 9. The upper end of the head 8 has a machined recess toreceive the lower. end of the extension 6 and is threaded at 10 to receivea settingtool or pipe whereby the eductlon tube maybe lowered into position during assembly,,] a

The eduction -,tube.has; a strainer nipple ll at its lower-end securedto the tube by a special coupling 12 having a cross-shaped spider l3" therein to; form .a stop for the V plungerleon its downward stroke. At the lower end of the tube extension 6, within the casmg head, said extension is slotted at to allow an 'outlet for the fluid-tothe discharge pipe '16. j The extensionisclosed at its upper e nd by a cap 17 inthe usual manner. 1

The plunger Mis'cylindricalon its outer periphery and has a downwardly convergingv inner bore'. fAt its lower end is secured a block or support of somewhat smaller outer diameter formed with a recess 18 to receive the valve lqv and support it in open position.

Said support is provided with an axial guide opening 20 to reoeive the, valve stem 21 which projects below the support when the valve isopen, and isadaptedto engage thestop I memberl3 and move the. valve upwardly into a seat 22. Thesupport 17 is provided with fluid openings above-the recess 18 as fseen at 23 to, allow fluid to pass through theplunger. 7 j I V The choke which'I provide for the plunger is placed within the upper end thereof. It comprises a disc 25 tapereddownwardly to fit within a seat26 formed in a ring ofmetal secured rigidly upon the inner face of plunger. The disc 25 is mounted upon a stem 27 which is threaded along its upper;

portion and projects through the upper guide bar 28. Nuts 29 and30 above and" below the guide bar make it possible to adjust the position of the disc 25 relative to the seat 26 in an obvious manner. A guide bar 31 below the seat serves to center the stem 27 for accurate operation.

In the operation of the swab, theplunger will drop. through liquid'at the bottom of the eduction tube with the valve 19 open and when it contacts with the stop member the valve will be forced shut; There will be a charge of liquid in. the eduction tube, before the plunger reaches this stop if the when contact occurs.

device is working properly so that there will be no excessive jar upon the valve or the stop The gas pressure accumulating in the well will raise the plunger with its load of liquid to the surface and the liquid load will be discharged through the slots 15 and the outlet pipe 16 The plunger I will then be blown past the-openings 15 with force suflicientto trapfluid in the extension 6 and thus the valve 19in the plunger will be forced open and the plunger will fall.

The gas below the plunger will be exhausting as the plunger falls and will have to pass through the open valve 19 and past the that the operation of the apparatus will be the passage of fluid through accurate and uniformand injury to the apparatus may be avoided. What I claim'as new is:

1. A pneumatic swab plunger "including a cylindrical tubular body, a valve seat at the lower end thereof, a valve to fit said seat, a support for said valve when said valve is open, and a choke device in said body above said valve adjustable to impede said plunger to the amount desired, 1

' 2. A pneumatic swab plunger including a tubular body, a downwardly opening valve therethrough.

in said plunger, and additional means to.

regulate the passage of fluid through said plunger.

4. In a neumatic swab device an eduction tube, a plunger movable from the low r end to the upper end thereof, a stop mem er for said plunger adjacent the lower end of said tube, a valve adapted to open at the upper. end of its travel and'additional'means in said plunger to regulate the passage of fluid therethrough and thus control the dropping of said plunger in said-tube to said stop member.

5. In agpneumatic swab device, an eduction tube, a tubular plunger having a'fluid passage therethrough and movable from end to end ofsaid tube, a stop for said plunger adjacent the lower end of said tube, a valve in said passage and additional means in said plunger to regulatethe size of said passage and thus control the movement of fluid 6. A pneumatic swab plunger comprising a tubular body having its upper end open, a valve to regulate the passage of fluid positioned at the lower end of said body, and means supportedon the inner wall of said body between the ends thereof to control the size of the passage through said body.

HAROLD W. FLETCHER. 

